Electric energy units are often expressed in “kilowatt-hours." (a) Show that one kilowatt-hour (kWh) is equal to 3.6 x 10° J. (b) If a typical family of four uses electric energy at an average rate of 580 W, how many kWh would their electric bill show for one month, and (c) how many joules would this be? (d) At a cost of $0.12 per kWh, what would their monthly bill be in dollars? Does the monthly bill depend on the rate at which they use the electric energy?

Q: An escalator is used to move 2.3 * 10' people (60 kg each) per minute from the first floor of a…

A: Given: number of people=2.3*101 = 23 mass of each people m = 60 kg height h = 5m time taken t = 1 m

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A: Given data: Mass (m) = 82.4 kg Power (P) = 1.0 hp Height (h) = 12.0 m 1 hp = 746 watts Required:…

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A:

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Q: 9.108. For a car weighing 980 kg, how much work must be done to move the car 24 miles? Ignore…

A: First, we must understand what is work done. Work is the energy transfer that happens when an object…

Q: In physics, what conditions must be satisfied if work is to be done?

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Q: A forklift raises a 90.5 kg crate 1.80 m. (a) Showing all your work and using unity conversion…

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Q: what is the total work done by the force over the distance x=0 to x=15.0m?

A: Work done is basically the area under the graph of Force vs displacement!

Q: - A weight-lifter does 4.4 x 10³ J of work in raising a weight from the floor to a height of 2.0…

A: Given  Work (w) = 4.4 × 103 J  Height (h) = 2 m  (a) let average force is ' F ' .   w = F× h…

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A: Mass of ninja warrior (m) = 59 kg  Length of ladder (L) = 9 m

Q: A mouse of mass 30.0 g falls 130 m down a vertical mine shaft and lands at the bottom with a speed…

A:

Q: What average mechanical power (in W) must a 61.5 kg mountain climber generate to climb to the summit…

A: The mechanical power of the climber can be found as, Here, W and t represent the work-done and…

Q: a helicopter lifts a 100kg crate straight up via cable, with an acceleration of 0.8m/s. if the crate…

A: mass = 100 kg acceleration = 0.8 m/s2distance = 5 m Apparent weight = m(g+a) = 100 (10+0.8) = 1080 N…

Q: How much work is done on a downhill skier by an average breaking force of 813 newtons to stop her in…

A:

Q: Calculate the total work done on a 1550-kg car as it coasts 20.4 m down a hill with f = 5.00°. Let…

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Q: Find the work done in joules by gravity as an object of the mass m=11 kg is raised up at constant…

A: Mass, m = 11 kg  Height, h1=29 m and h2=78 m  Acceleration, a = -g = -10

Q: In climbing up a rope, a 62-kg athlete climbs a vertical distance of 5.0 m in 9.0 s. What minimum…

A: Given Data: The mass of an athlete is m=62 kg The vertical distance is, d=5 m The time required to…

Q: ,2 54. A 5.0-kg box has an acceleration of 2.0 m/s when it is pulled by a horizontal force across a…

A:

Q: Cite an example wherein  force exerted on a body does no work. Explain.

A: Work done is defined as the product of force, displacement and cosine of angle between force and…

Q: How much work is done by gravity when dead lifting a 100.0 kg barbell 81.54 cm from the floor to hip…

A:

Q: A record was set for stair climbing when a man ran up the 2300 steps of the Empire State Building in…

A: Average power output is,

Q: A 70 kg hiker climbed a mountain 1000 m high. Assuming the work was done at a steady rate during 3…

A:

Q: In a training, you are doing a vertical climb using a rope to lift yourself by 5.0 m in 2 s. If you…

A: Given data: Height (h) = 5.0 m Time (t) = 2 s Mass (m) = 55 kg Required: Work done (W) and Power…

Q: .How much work is required to move an object from x=2 to x=4 (measured in merters) in presence of…

A: Given:  F(x) = 4 / x2 from x = 2 m to x = 4 m

Q: If it requires 9.0 J of work to stretch a particular spring by 2.0 cm from its equilibrium length,…

A: The energy required to stretch the spring is

Q: How many joules of energy does a 100 watt light bulb use per hour? How fast would a 70 kg person…

A: The power is defined as the energy per unit time, P=Et Use the given values, E=P×t=100 W×3600…

Q: What is the average useful power output (in w) of a person who does 6.80 x 106 J of useful work in…

A: Given: Work done by the person, W = 6.80 × 106 J time taken to complete it, t = 7.60 h = 7.60 h ×…

Q: For saving energy, bicycling and walking are far more efficient means of transportation than is…

A: Egas = 1.3 x 108 J/gal 1 kcal = 4186 J Vb = 11 mi/h Eb = 400 kcal = 400 x 4186 = 1.67 x 106 J Vw = 3…

Q: What average mechanical power must a 70.0 - kg mountainclimber generate to climb to the summit of a…

A: Using Work-Energy theorem,

Q: An escalator is used to move 2.1 * 10' people (60 kg each) per minute from the first floor of a…

A:

Q: What average mechanical power (in W) must a 60.0 kg mountain climber generate to climb to the summit…

A: solution as

Q: What average mechanical power (in W) must a 70.5 kg mountain climber generate to climb to the summit…

A: The expression for the average mechanical power (P) is,

Q: Find the work done in joules by gravity as an object of the mass m=7 kg is raised up at constant…

A: The mass of the object is 7 kg.  The initial height is 40 m.  The final height is 67 m.  The work…

Q: What average mechanical power (W) must a 76.5kg mountain climber generate to climb to the summit of…

A: Given that: m=76.5 kgg=9.8 m/s2h=405 mt=46 min=2760 sec W=?

Q: How much power is required to raise a 30-kg crate a vertical distance of 6m in a time of 4 seconds?…

A: The potential energy of a body is given by PE = mgh, where m = the mass of the body g = acceleration…

Q: Calculate the horsepower needed for a 1200-kg car to climb to an altitude of 1000 m from sea level…

A:

Q: A ship with a displacement of 20,000 T accelerates from 14 knots to 17 knots over a period of 30…

A: Given Data: Mass of ship, M=20,000 T=18143695 kg or 1.81×107Kg Initial velocity, u=14 knots=7.196…

Q: While cruising along a level ground in a one horse open sleigh at 4.0 m/s, Santa cracks the whip and…

A:

Q: The 2018 Pyeongchang gold medalist winner in a large hill ski jumping discipline, Kamil Stoch,…

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Q: Find the work done in joules by gravity as an object of the mass m=6 kg is raised up at constant…

A: Here, we are given Mass of object, m = 6 Kg Initial height of the object from the ground, h1 = 32 m…